Integration of Sentry Visibility Sensor into Campbell Scientific Data Logger CR1000 *

Transcription

1 Available online at Procedia Environmental Sciences 12 (2012 ) International Conference on Environmental Science and Engineering (ICESE 2011) Integration of Sentry Visibility Sensor into Campbell Scientific Data Logger CR1000 * Chen Yonghua Institute of Oceanology, Chinese Academy of Sciences Qingdao, Shandong Province, , China yonghuachen@yahoo.cn Abstract In this paper, how to integrate Sentry Visibility sensor with Campbell Scientific CR1000 series data loggers is described. The CR1000 is the product of Campbell Scientific, which provides precision measurement capabilities in a rugged, battery-operated package. It consists of a measurement and control module and a wiring panel. Standard operating range is -25 to+50 and it is widely used to get data. SVS1 Sentry Visibility Sensor measures atmospheric visibility (meteorological optical range) by determining the amount of light scattered by particles (smoke, dust, haze, fog, rain, and snow) in the air that pass through the optical sample volume. The detailed integration steps between the data logger CR1000 and SVS1 Sentry Visibility Sensor is given. The steps include: 1) establish communication with SVS1 Sentry Visibility sensor via RS-232 port of PC: 2) write down the instrument communication parameter settings. 3) make necessary electrical and data line connections to data logger. 4) program the data logger to acquire data from Sentry Visibility Sensor. Practice proves that the acquisition method is feasible Published by Elsevier by Elsevier B.V. Selection Ltd. Selection and/or peer-review and/or peer-review under responsibility under responsibility of National University of [name of Singapore. organizer] Open access under CC BY-NC-ND license. Keywords:Data logger CR1000; Sentry Visibility Sensor; integration. 1. Introduction One important step in scientific research is to observe a phenomenon for a period of time and collect data. Conclusions are drawn after analyzing the data. As much as it is important to collect data, how data are collected is equally vital. The quality and reliability of the data acquisition system are of utmost importance since unreliable data can result in wrong conclusions[1]. Besides being expensive and * This research was supported by the National Natural Science Foundation of China under Grants No and No Published by Elsevier B.V. Selection and/or peer-review under responsibility of National University of Singapore. Open access under CC BY-NC-ND license. doi: /j.proenv

2 1138 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) ineffective, such tests can even jeopardize human life and property. Therefore, it is crucial to design a proper test system with accurate, reliable, repeatable, stable data collection systems including sensor. Campbell Scientific and EnviroTech, two leading companies in their fields, provide components of a scientific data acquisition system to collect data to observe geophysical and environmental applications. Campbell Scientific designs and manufactures data loggers. EnviroTech designs and manufactures high accuracy weather sensor including wind, temperature, humidity, precipitation and pressure. Campbell Scientific data loggers and EnviroTech sensor instruments are widely used to capture weather data. 2.Campbell Scientific CR1000 Data Logger and SVS1 Sentry Visibility Sensor Data loggers are highly accurate voltmeters that are a part of a data acquisition system that converts electrical signals into data and stores them in its internal memory. Data loggers can measure most sensors with electrical output. The CR1000 is a low power, wide temperature range data logger with flexible programming and telecommunication options[2]. It comprises the most advanced data logging technology from Campbell Scientific. It provides precision measurement capabilities in a rugged, battery operated package. The data logger includes a CPU and analog and digital inputs and outputs. The on-board programming engine includes data processing and analysis routines. LoggerNET, PC200 and PC400 software provide program generation, editing, data retrieval and real-time monitoring. Performance in all weather conditions was a design prerequisite for the sentry. An integrated, one-piece housing design keeps all cabling internal to the sensor for the ultimate protection against the elements. The sensor housing is made from anodized aluminum and the enclosures are rugged, UV-resistant fiberglass rated to IP66. Based on the proven experience of the NWS and FAA, the sensor uses a "look down" geometry to reduce window contamination and clogging from blowing snow. The windows use continuous duty anti-dew heaters and thermostatically controlled external hood heaters are offered for protection in extreme environments. All power and signal lines to the sentry are protected with surge and EMI filtering to help guarantee uninterrupted service for the life of the sensor. Installation and maintenance effort is minimal for the sentry. An 1-1/2 inch IPS pipe or optional 1 inch IPS pipe flange located on the bottom of the Main Electronics Box mates with a user supplied pipe. Power and signal connections are made through waterproof cable glands to terminal boards in the Box[3]. Calibration of the sentry in the field is as simple as connecting a factory supplied calibration fixture and following a simple procedure that takes less than 30 minutes. Annual calibration is recommended. EnviroTech Sensor provides dependable, relevant, real-world solutions. The Sentry Visibility Sensor works continuously in all weather conditions to monitor changes in visibility due to rain, snow, fog, smoke and dust[4]. 3.Installation/Integration Steps CR1000 data logger has 16 SE (single ended) or 8 differential channels (DIFF) and four COM ports to read data from external sensor. EnviroTech sensor can be interfaced via either of the following types of ports on the CR1000 data logger. The port selection decision is mostly dictated by application: 9-pin RS-232 (not isolated) port CS I/O Port (Campbell Scientific Input/Output) COM ports (marked in blue) In most cases, since there will be other products or accessories using the 9-pin RS-232 or the CS I/O port, this technical note will focus on integrating the Digiquartz Intelligent products via the COM ports (TX/RX lines). In this paper, we assume that COM1 is used for integration. The connection of a Sentry Visibility Sensor to a CR1000 has the following steps. It is assumed that you have already established communication between PC and data logger and set the necessary configuration parameters in data logger.

3 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) Verify/establish communication with SVS1 Sentry Visibility Sensor via COM port of PC. Write down the instrument s communication parameters. Make the necessary electrical and data line connections to CR1000 data logger. Program the data logger to acquire data from SVS1 Sentry Visibility Sensor. Verify that the logger is acquiring and storing data. Locally or remotely download/view data. 3.1.Verify/establish communication Load SVS1 Sentry Visibility Sensor Software that came with intelligent product on PC. Connect the intelligent product to the RS-232 port of PC. Launch the software and detect the intelligent unit automatically. Once the unit is detected and communication is established, see Fig. 1. Write down the instrument ID, ComPort number, baud rate, and parity from this window. Figure 1. Communication Startup Form 3.2.Make necessary electrical and data line connections Disconnect the intelligent instrument from the PC. Connect the intelligent instrument to the CR1000. Locate the pin numbers for the pins labeled in Table 1 below. Pin numbers can be found either on the product Specification Control Drawing (SCD) or in the product user s manual delivered with the intelligent product. Write the pin numbers in the table below. Table 1 Pinout Table Pin Signal Connection on CR1000 RS-232 TX COM1 RX RS-232 RX COM1 TX Ground G Power 12V Connect each pin in Tab. 1 to its location in Fig. 2. Figure 2. CR1000 COM1 Data and Electrical Connection

4 1140 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) Connect the RS-232 TX and RX wires first. Make sure that the TX wire from the sensor is connected to RX port of COM1 and RX wire to TX port. Connect ground wire to G and power wire to 12V terminal on the CR1000. Tighten the screws and make sure that there is contact between the sensor RS-232, power and ground wires and the screws on each port. 3.3.Program the data logger A program must be provided for the data logger in order to make` measurements and store data. The CR1000 data logger has a total memory of 2 MB. Approximately 1400 Kbytes of memory is available for data table storage. Additional storage space can be provided by using an optional compact flash card. The memory has battery back up. When power is lost or the data logger is powered down, programs and data remain in memory. If power is lost, an active program will start running again when the power is back. Stored data is maintained in table format. In addition to data tables, there are public and status tables. The public table holds variables and the status table holds variables that define logger status. Each data table has its own file. Tables are erased when program is loaded and run. The number and size of data tables is defined by the individual CR1000 program. Numerous data tables can be used to store different data on different intervals. The CR1000 can auto allocate its tables; so, the newest data begins to overwrite the oldest data at approximately the same time. There is a field in the Status Table that indicates how long it will take before the oldest data in the table is overwritten by the newest data. There are several ways to program the CR1000. The simplest way is to use Campbell Scientific s software called ShortCut. For more complex programming, the CRBasic editor can be used. Figure 3. LoggerNet Software Interface The best way to program and manage CR1000 is to use Campbell Scientific s LoggerNet software. LoggerNet is a comprehensive data logger support software package that provides communications, data logger program editing, data processing and viewing. Please follow the steps below to read data from products. Make sure that the product is connected to the data logger and powered as described above. We can use a voltmeter to verify that there is power applied to the visibility sensor. (Measure the voltage between power and ground pins). It is assumed that we have already configured CR1000. If we have not done so, consult the CR1000 user s manual to configure the data logger. The data from the visibility sensor can be visibility, visibility period. Program the data generic logger program on how to integrate visibility sensor to the CR1000 data logger. In this program, disable the parameters we don t need. The source code for reading visibility only is available. Click on the Connect icon in LoggerNET to launch the program as illustrated in Fig. 3. Click on the Connect button on the program window to connect to the data logger.

5 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) Figure 4. Connect program window Communication with logger will be established and the following screen will appear (See Fig. 5). Set date/time information in this window if needed. Figure 5. Connect program window displaying CR1000 Logger parameters Click on the Send button in the Program group. This will bring up an Open dialog box. Select the program file to send to the CR1000 ( AllParams.cr1 in the example). When we click on the OK button the message box in Fig. 6 will appear. Sending a program to the logger erases all the stored data. Figure 6. Program upload warning box Click on OK to transfer and compile the program to the logger. If the program states that you successfully uploaded the program, then you are ready to collect data. To verify that logger is reading data, click on the Numeric 1 button in the Data Displays group. This will open a window in Fig. 7.

6 1142 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) Figure 7. Program upload warning box Add the parameters we would like to display in this window. Select a cell in the gray area in Fig. Click on the Add button. The window in Fig. 8 will appear. Figure 8. Tables and Parameters Fig. 8 shows the tables and fields in each table. The public table will show all the public parameters defined as Public in program. The Digiqrtz table shows the values of parameters logged most recently. To see how the program works, add parameters from the Public table and the Digiqrtz tables as in Fig. 9. In Fig. 9, the parameters on the left are public variable; the ones on the right are parameters from the Digiqrtz table defined in the program. Figure 9. Verifying data logger operation real-time

7 Chen Yonghua / Procedia Environmental Sciences 12 ( 2012 ) If all of the public parameters (the group on the left above) are updating periodically, this means program is communicating with instrument and reading data. If the parameters from the Digiqrtz table are updating periodically, this means the program is also logging data. At this point, we can exit from the program and let the CR1000 continue logging data. To set the logger into delayed logging mode, use the EZSetup software that comes with LoggerNet. See software user s manual to explore the details of the EZSetup option. To download logged data to PC, again use the Connect program and click on the Collect Now button in the Data Collection group. This option allows you to download the data to a text file. This text file can easily be imported into an MS-Excel spreadsheet. LoggerNet can also be programmed to download data periodically. Acknowledgment I thank senior engineer S.R. Li and engineer J.B. Jiang for technical help. This research was supported by the National Natural Science Foundation of China under Grants No and No References [1] M. Benghanem, A low cost wireless data acquisition system for weather station monitoring, Renewable Energy, vol.35, pp , [2] CR1000 Measurement and Control System brochure, [3] A. Y. Sultan, C. Yassine, G. Adel, A. A. Saleh, Assessment of wind energy potential locations in Oman using data from existing weather stations, Renewable and Sustainable Energy Reviews, vol.14, PP , [4] A. C. Ameida, J. J. Landsberg, Evaluating methods of estimating global radiation and vapour pressure deficit using a dense network of automatic weather stations in coastal Brazil, Agricultural and Forest Meteorology. vol.113, PP , 2003.